Process for determining Reference Quality bitstreams (RQx) At any time, if evidence is presented (i.e. listening test results) that show that an Alternate Encoder (AE) shows an improvement over RQx at the 95% level of significance, then AE becomes the new Reference Quality Encoder (RQx+1).
Stephan Schreiner
Wolfgang Fiesel
Matthias Neusinger
The contribution notes that HE-AAC is getting widespread adoption in the video broadcast marketplace. However, relative to some competing audio coding systems, HE-AAC has limited support for metadata and which in turn might limit market adoption. The metadata of greatest interest is information to control the following three factors (the three "classical" D's):
Clean Audio – boost dialog and suppress ambiance for e.g. hearing impaired listeners
The contribution reviewed the limitations of the metadata currently supported by AAC (and hence available to HE-AAC) and proposes a potential requirements for a potential metadata activity:
Embedding in coded representation (bitstream) – retain backward compatibility
There was considerable discussion on this topic. An issue was raised as to whether the metadata is agnostic to and independent of the coded representation. Another comment was whether metadata is even needed to provide the user control functionality.